Technologies are known that use radiation to analyze or inspect an object (referred to as a detected object). Among these, since X-rays are electromagnetic waves having energy of about 100 eV or more, non-destructive inspection methods using X-rays are used in a wide range of fields from industrial uses to medical uses.
For example, techniques have been proposed for quantitatively obtaining physical property values of detected objects by utilizing the absorption or phase shift of X-rays attributable to the detected object.
PTL1 describes a method for acquiring information on electron density distribution or effective atomic number distribution of a detected object from two or more X-ray absorption-contrast images by utilizing monochromatic X-rays having two or more energy levels (wavelengths).
In addition, PTL2 describes a method for acquiring effective atomic number distribution of a detected object from information on X-ray absorption and phase shift attributable to the detected object.